Tuning device for radiocircuits



M. B. wRoBLEY TUNING DEVICE FOR RADIO cmc'uns Jan. 8, 1929.

Filed May 21, 1925 2 Sheets-Sheet Jan. 8, 1929.

M. B. WROBLEY TUNING DEVICE FOR RADIO CIRCUITS Filed May 21, L925 2Sheets-Sheet 2 [nu/nib?" Patented Jan. 8, 1929.

MATTHEW B. WROIBLEY, 01 DENVER, COLOEBIADO.

TUNING DEVICE FOR RADIOCIBCUITS.

Application filed May 21, 1925. Serial No. 31,950.

' It is the object of this invention to produce a device which willfacilitate the tuning of radio circuits which have several condensers,

reactances 01' inductances that require substantial'ly the sameadjustments and has reference more specifically to an improvedconstruction and combination of elements by means of which severalvariable tuning units may be simultaneously moved to the same extent soas to obtain a. rough tuning and which permits the several units to bemoved independently of each other to obtain the fine adjustments. Y

My invention, briefly described, consists in attaching to each tuningunit a separate handle by means of which it can be adjusted,

and to bring portions of said handles into juxtaposition with each otherso that they may all be engaged by a movable pin for the purpose ofadjusting all at one time but which can also be engaged separately foraccomfiner adjustments. In order to plishing the employ my invention tothe best advantage it is desirable to provide a'plurality of movablename plates along the path of the adjusting handles so that the exactpositions of the handles for the several wavelengths may be logged.

In order more clearly to describe my inven- 3 .-tion and the manner ofusing the same. Ishall have reference to the accompanying drawings inwhich it has been illustrated and in which: Fig. 1 is a front view, inelevation, of one embodiment of my invention: Fig. 2 is an end elevationof the parts shown in Fig. 1; v

Fig. 3 is a top plan view of the parts shown in Figures 1 and 2;

Fig. 4 is a top plan view of a modified form my invention; Fig. 5 is a.front elevation of the device shown in Fig. 5 and;

Fig. 6 is a plan view of one of the adjustable name plates.

In Figures 2-and 3 the reference numeral 1 is the cabinet and thatindicated by numeral 2 the front side thereof. As my invention relatesto a portion only of the radio receiver, I have 50 purposely refrainedfrom complicating the disclosure by the inclusion of parts that do notcooperate with it. Referring now more particularly to Figs. 2 and 3 Ihave shown three multiple plate condensers 3 arranged 55 in a line. Thestators which have been designated by the reference character 3 aresecured part indicated by base of the radio ened part of the to the base1 by any suitable means such, for

example, as screws. I have illustrated multiple plate condensers butthese may be replaced by variometers or any variable tuning devices maybe employed and adjusted in the same manner. Each condenser has a rotor3 which is nonrotatably secured to a shaft 5 that in turn is rotatablymounted in the brackets 4. The stands or brackets 4.- are arranged sothat the several short shafts 5 are coaxial or concentric with respectto each other.- Secured to but electrically insulated from each of therotors is a lever; these levers have been designated by numerals 6, 7and 8. The side 2 of the cabinet is a segmental cylindrical member whosecenter of curvature coincides with the center of the shaft 6 and has aslot 9 through which the outer ends of the levers 6, 7- and 8 project.The extreme ends of the levers are flattened so as to produce handleportions 6, 7 and 8 that are adapted'to be grasped by the hand of theoperatorwhen tuning the circuits. my desire to move all of the leverssimultaneously, it is essential that the handles shall be located may beaccomplished in several ways but I --have shown lever 7 as extending ina direction parallel with its plane of rotation while levers 6 and 7 arebent towards it so as to bring the handles close together. The sameresult could, of course, be obtained by having one of the levers 6 or 8.straight and the others bent. Extending parallel with the slot 9 is anarrow slot 35 which is adapted to receive the name either members thatshow the wave length to which that particular location corresponds orletters indicating the station to which the particular location of thelevers corresp'on The construction of these name plates s shown in Fig.6. The plates 30 have a tran versely extending portion of greater thic'ness than the ends so as to providetwo parallel shoulders 31 that arespaced apart a distance that equals the width of the slot 35. A stud 32projects from the rear of the thicka spring 33 that is bowed in themanner shown in Fig. 6. The than the width of the slot so that it may beinserted from the front andwhen the plate is in place the ends of thespring rest upon the inner surface of the side 2 and holds the platewhich may, however, be moved by applying sufiicient force.

As it is as close together as possible. This plates 30 that carry ontheir faces plate and has secured to it width of this spring is lessWhen the operator desires to adjust the circuits he grasps all threehandles and moves them into a position adjacent the name plate thatrepresents the station he wants to tune in on. Bythis simultaneous adjfiment the circuits are roughly 'tuned. He S'w completes the tuning bymoving each lever independently until the best results are attained. Itis, of course, possible to move each lever separately to any extentdesired, but since they must all be moved to substantially the sameposition, the method described is the quickest and best.

In Figs. 4 and 5, I have shown a modification which also contains meansto still furthersimplify the operation of the radio set. In Figs. 4 and5 numeral represents the base and 11 the front end of the cabinet. curedto the base 10 are three stators 12, 13 and 14? of condensers 12, 13 and14. The rotors 12 13 and 14* are each secured respectively to andinsulated from the concentric shafts 15, 16 and 17. The largest shaft,which has been designated by numeral 7 17, has one end journalled in thebore 19 of the side 11 and is rotatably carried by shaft 16 which inturn is rotatably carried on the smallest shaft whose inner end issupported in the stand or bracket 18. Since it is necessary to be ableto rotate each shaft independently of the other two, I have providedeach shaft with a friction device comprising springs 20 which have parts21 that are fastened to the base 10. These springs are adjusted so thatthe friction produced by them is sufiicient to hold the shaft fromrotation when either of the othershafts are rotated, thereby making itpossible to make individual adjustments.

Secured to. the outer ends of the shafts 15, 16 and 17 are armsor levers24, 23 and 22 respectively. The outerends of these arms haveflattenedhandle portions 24*, 23 and 22' respectively. Shaft 15 isprovided with an extension 15 which forms a pivot for the disk 25 thatis held against withdrawal by means of the head 15". The disk 25 has twospaced pins 26 extending inwardly therefrom; these pins embrace thelevers the manner shownin Fig.5 and are spaced apart a somewhat greaterdistance than the thick ness of the levers so that the lattermaybeindependently adjusted to a limited extent. By rotating the plate 25in either direction one or the other of the pins 26 will e "age theleversand move them all together into position adjacent the desired nameplate 30; this gives the initial rough adjustment. Each leveris nowindependently adjusted so as to get the'best result.

The plates 30 shown in Fig. 5 are constructed as above described and aremovable in the slot 26. The ends'of the levers or handles, in bothembodiments, also serve as pointers or indicators but other indicatorsmay be used if desired.

After the plates 30 have once been adjusted for a special wave length,the circuits may be quickly tuned to this Wave lengthby mov-- ing thehandles until ticular plate.

. Although I have described a specific embodiment of my invention, thishas been done for the purpose of illustration only and this disclosureshould therefore not be considered they point to this paras limiting.the invention to any greater extent than what may be necessary for thepurpose of avoiding the prior art.

Having now described my invention what Iclaim as new is: Y

1. A radio tuning device comprising, in combination, a plurality ofvariable tuning units adapted to be connected into. the circuits of aradio reception apparatus for varying the electrical characteristics ofthe circuits, each of said units having a stationary part and a movablepart, said movable parts being adapted to oscillate about axes that arein substantial alignment, an adjusting member secured to each of saidmovable parts,

said members each having a portion that lies parallel with thecorresponding portion of the adjacent member, said portions beingadapted to move in substantially parallel paths and means for adjustingsaid movable members simultaneously, said means having spaced lugsadapted to engage all of said movable members. i

2. A radio tuning device comprising, in combination, a pluralityofvariable tuning units adapted to be connected into the circuits of aradio reception apparatus for varying the electrical characteristics ofthe circuits, each of said units having a stationary part and a movablepart, said movable parts being adapted to oscillate about-axes that arein substantial alignment, an adjusting member secured to each of saidmovable parts, said members each having a portion that lies parallelwiththe corresponding portion of the adjacent member, said portions beingadapted to move in substantially parallel paths, means movable about theaxis of .said movable members and a plurality of name plates adjustablylocated in a path parallel with the path of movement of said adjustingmembers.

In testimony whereof I a-flix my signature.

MATTHEW B. WROBLEY.

